Currently, electric vehicles are basically classified into pure electric vehicles and hybrid electric vehicles. A pure electric vehicle has a drawback that the limited capacity of its battery results in a relatively short continuous mileage, and the electric vehicle will not work if the battery is abnormal or empty during the drive. Moreover, since the battery is the only source to supply power to the pure electric vehicle, the battery is usual continuously discharged for long periods during using, which has a great influence to the service life of the battery. In a hybrid electric vehicle, a fuel generator is added on a basic structure of the pure electric vehicle, and the above drawback of the pure electric vehicle is overcome. However, the hybrid electric vehicle brings some new problems, which are mainly in the following aspects. Firstly, the fuel that it uses is non-renewable resources. When fuel is burned during the car driving, carbon dioxide gas is exhausted, which causes heavy pollution to the environment and is adverse to the concept “green travel” promoted in the world. Secondly, the continuously rising of fuel prices increases the cost of using hybrid electric vehicle. Therefore, it has been a problem pressing for solution in the electric vehicle technical field to design a novel electric vehicle that has an enhanced continuous mileage and a prolonged service life of the battery, and meanwhile is environmentally friendly.